It's amazing how time flies - 10 days since the last update, and more mystery to report.
At the last count we have had a single queen in our outdoor colony and she was busy collecting liquid supplies for, what we presume, was a colony she has been brooding. Over the last 10 days we've continued to see her coming and going and drawing from the supplies we have been offering, though oddly not collecting any pollen: usually a key initial role for brooding queens. None-the-less we assumed this was what she was up to until things took an unusual turn yesterday.
My suspicions were first aroused when I saw what I thought was the queen resting on the inside roof of the box for what has now been (at the time of writing) almost 28 hours. Has barely moved, nor fed. On closer examination of the CCTV it turns out this is a female bumblebee from outside. I know her identity exactly as I actually marked her: she has been coming to feed on our supplies of honey water and also collecting pollen (so not a cuckoo) - but for another nest. For some reason yesterday she came into our nest (with surprising great ease via the flap, I might add) and has stayed there (very still) since.
Oddly, not long after she arrived, our queen went out (about 7.15pm on 28th July) and at the time of writing has not returned. This is rather confusing and concerning - we wonder whether she has intentionally abandoned the nest, or went out foraging and met with difficulties, but it's now been 26 hours or so. We've seen this kind of thing before, and happy outcomes, but not with a seemingly brooding queen - it doesn't make sense. Whether it coincides with a change in the weather from a spell of record-breaking hot days to much wetter and cooler weather, who knows? Of course, we had not been looking inside the nest to see what was going on for fear of causing the queen to flee - but she may have done for some reason anyway.
Once again, we find ourselves waiting with certain trepidation.
The incredible news from our indoor colony of disabled bumblebees is that Dusty is now at least age 101 days and Nedine at least 99. (We say at least because that's how many days we've had them in care - they may have been several days old when we found them).
These are truly remarkable numbers for worker bufftails who generally are thought to only live a few weeks (maybe 3 - 6). In general they are both still as active/energetic as ever and we continue to supply occasional bits of bedding for dusty to organise (it's her role) and new pollen for Nedine to work with (that seems to be her role). We are working on the basis that new research into bees shows that social roles in the nest can extend their lifetime and mental capacity, and that it might also apply to bumblebees.
The less good aspect is that dusty is showing some apparent signs of her age. Despite being energetic she has started being apparently less co-ordinated and shaking a bit more. It is not (yet) the classic symptom we have seen of bumbles becoming weak and unstable, but it is definitely a change. She falls over a lot (but is able to right herself) and doesn't make good progress when she walks - tends to be two steps forward, one step (or fall) back. On some occasions it seems like maybe her eyesight just isn't so good - but on others it seems more like something neurological (akin to dementia or Parkinson's in humans). She also seems to have lost most of her colour - only two very slight yellow flecks remaining on her shoulders.
We are closely monitoring her.
You can see in the video below, she is quite energetic, but sort of "frantically dysfunctional"